1. Field of the Invention
The present invention relates to an electron-emitting device and an electron source using the same and an image display apparatus using the same. Moreover, the present invention relates to an information reproducing apparatus such as a television receiver that receives a broadcast signal of a television broadcast and displays and reproduces image information, character information, and voice information, which are included in the received broadcast signal.
2. Description of the Related Art
A conventional process for manufacturing a surface conduction electron-emitting device is schematically shown with reference to FIG. 17. First, a pair of auxiliary electrodes 2, 3 are formed on a substrate 1 (FIG. 17A). Next, the pair of auxiliary electrodes 2, 3 are connected to each other by a conductive film 4 (FIG. 17B). Then, a voltage is applied between the pair of auxiliary electrodes 2, 3 to form a first gap 7 in a portion of the conductive film 4 (FIG. 17C). This processing is called “current passing forming”. The “current passing forming” processing is a process of passing a current through the conductive film 4 to form the first gap 7 in the portion of the conductive film 4 by joule heat developed by the current. A pair of electrodes 4a, 4b opposite to each other across the first gap 7 are formed by the processing of “current passing forming”. Then, the pair of electrodes 4a, 4b are subjected to processing called “activation”. The “activation” processing is processing such that a voltage is applied between the pair of auxiliary electrodes 2, 3 in an atmosphere of gas containing carbon. With this processing, a conductive carbon film 21a, 21b can be formed on the substrate 1 in the first gap 7 and the electrodes 4a, 4b near the first gap 7 (FIG. 17D). An electron-emitting device is formed by the foregoing processing.
FIG. 16A is a plan view to schematically show an electron-emitting device subjected to the foregoing “activation” processing. FIG. 16B is a schematic cross-sectional view along a line B-B′ in FIG. 16A, which is basically equivalent to FIG. 17D. In FIG. 16A and FIG. 16B, parts denoted by the same reference numbers as shown in FIG. 17 denote the same parts as shown in FIG. 17. When electrons are emitted from the electron-emitting device, an electric potential applied to one auxiliary electrode 2 or 3 is made higher than an electric potential applied to the other auxiliary electrode 3 or 2. When the voltage is applied between the auxiliary electrode 2 and the auxiliary electrode 3 in this manner, a strong electric field is developed in a second gap 8. As a result, it is thought that electrons tunnel from many points (a plurality of electron-emitting parts) in a portion that forms the end edge of the carbon film 21a or 21b connected to the auxiliary electrode 3 or 2 on the lower electric potential side and forms the outer edge of the second gap 8, and that at least some of the electrons are emitted.
In the below-listed patent documents 1 to 6 there is disclosed a technology for controlling the shape of the foregoing auxiliary electrodes 2, 3 and the shape of the conductive film 4 to control the position of the gap.
An image display apparatus can be constructed by arranging a substrate having an electron source constructed of a plurality of electron-emitting devices of this kind opposite to a substrate having a fluorescent film formed of a fluorescent substance or the like and by keeping the interior of the two substrates in a vacuum.
[Patent document 1] Japanese Patent Application Laid-Open No. 1-279557
[Patent document 2] Japanese Patent Application Laid-Open No. 2-247940
[Patent document 3] Japanese Patent Application Laid-Open No. 4-094032
[Patent document 4] Japanese Patent Application Laid-Open No. 4-132138
[Patent document 5] Japanese Patent Application Laid-Open No. 7-201274
[Patent document 6] Japanese Patent Application Laid-Open No. 8-096699